US telecoms firm Verizon has agreed to buy online portal Yahoo for roughly five billion dollars, according to reports.
The deal is expected to be announced formally before markets open on Monday.
Verizon had emerged in recent days as the frontrunner for the beleaguered internet company.
Yahoo is expected to sell its email service and news, finance and sports websites in addition to its advertising tools under pressure from shareholders who have grown weary with a downturn in the company's revenue during the past eight years.
After the sale is completed, Yahoo will become a holding company for its two stakes in China's e-commerce leader, Alibaba Group, and Yahoo Japan.